Clinical Utility of Chromosomal Microarray Analysis of DNA from Buccal Cells: Detection of Mosaicism in Three Patients

Mosaic chromosomal abnormalities are relatively common. However, mosaicism may be missed due to multiple factors including failure to recognize clinical indications and order appropriate testing, technical limitations of diagnostic assays, or sampling tissue (s) in which mosaicism is either not present, or present at very low levels. Blood leukocytes have long been the “gold standard” sample for cytogenetic analysis; however, the culturing process for routine chromosome analysis can complicate detection of mosaicism since the normal cell line may have a growth advantage in culture, or may not be present in the cells that produce metaphases (the lymphocytes). Buccal cells are becoming increasingly utilized for clinical analyses and are proving to have many advantages. Buccal swabs allow for simple and noninvasive DNA collection. When coupled with a chromosomal microarray that contains single nucleotide polymorphic probes, analysis of buccal cells can maximize a clinician’s opportunity to detect cytogenetic mosaicism. We present three cases of improved diagnosis of mosaic aberrations using buccal specimens for chromosomal microarray analysis. In each case, the aberration was either undetectable in blood or present at such a low level it likely could have gone undetected. These cases highlight the limitations of certain laboratory methodologies for identifying mosaicism. We also present practice implications for genetic counselors, including clinic workflow changes and counseling approaches based on increasing use of buccal samples.     

Short-term memory and working memory as indices of children's cognitive skills

In the current literature, empirical and conceptual distinctions have been drawn between a more or less passive short-term memory (STM) system and a more dynamic working memory (WM) system. Distinct tasks have been developed to measure their capacity and research has generally shown that, for adults, WM, and not STM, is a reliable predictor of general cognitive ability. However, the locus of the differences between the tasks has received little attention. We present data from children concerning measures of matrices reasoning ability, reading, and numerical skill along with forward and backward order serial recall of WM, STM, and STM with articulatory suppression tasks. As indices of children's cognitive skills, STM and WM are shown to be rather similar in terms of memory per se. Neither the opportunity for rehearsal nor task complexity provides satisfactory explanations for differences between memory tests.     

Modifying driver behaviour with passenger feedback

A feedback programme was employed to help drivers improve their safety behaviour based on the idea that particular types of driver error result from contingency traps as defined by Fuller [Journal of Applied Behaviour Analysis, 24 (1991) 73]. Two drivers and their single respective passengers participated. For each driver, repeated in-car observations were made of four unsafe driving behaviours. Two of these were sequentially targeted in the behavioural intervention that involved the passengers providing informational feedback to their driver. Both drivers showed a marked improvement across the targeted behaviours. The study demonstrated the applicability of behaviour analysis to the traffic domain and the efficacy of individual feedback as a behavioural tool for positive behaviour modification.     

Theme-focused family therapy: the inner emotional world of the family

This paper is an account of a method of family work developed for social workers in social services departments which allows them to work with the emotional impact on children and adults of traumatic events in family life. Theme-focused family therapy has been designed to meet the needs of the families and also to enable social workers and their supervisors to develop both psychodynamic and systemic perspectives m their work with families. It is a staged approach, moving from individual work to a structured family interview through to a series of theme-focused family sessions. It is phased in this way both to facilitate the development of a therapeutic attachment between social worker and family and to take account of the crises that can interrupt planned work in social services departments. Theme-focused family therapy is carried out in partnership with families, and gives children a voice and a leading role in the therapeutic process. The approach is illustrated with a case example.     

A constrained optimization model of risky decisions

A decision model is formulated for individual choices between gambles whose probabilities and payoffs are explicitly stated. The decision situation is characterized as R_N = (X, P, Z, T, α) where X is a payoff matrix, P is the objective probability distribution over the states of nature, Z is a class of objective functions, T is tolerable regret and 1 ? α is the maximum probability for accepting regrets greater than T. Given R_N, the problem of selecting a strategy is the solution of a chance constrained optimization problem. The solutions for choice situations having two alternatives and n states of nature are developed in a series of theorems. Some implications for experimentation and possible applications are discussed.